Identification of Chlamydia pneumoniae proteins in the transition from reticulate to elementary body formation.

Chlamydia pneumoniae is an important human respiratory pathogen that is responsible for an estimated 10% of community-acquired pneumonia and 5% of bronchitis and sinusitis cases. We examined changes in global protein expression profiles associated with the redifferentiation of reticulate body (RB) to elementary body (EB) as C. pneumoniae cells progressed from 24 to 48 h postinfection in HEp2 cells.

Evidence from ESR studies for [Co(eta-C2H4)3] produced at 77 K in a rotating cryostat.

Co atoms were reacted with ethene at 77 K and the paramagnetic products studied by electron spin resonance (ESR) at X- and K-bands. The ESR spectra of the major product at both frequencies showed eight cobalt multiplets (ICo=7/2) indicating a mono-cobalt complex. The spectra have orthorhombic g and cobalt hyperfine tensors and were simulated by the parameters; g1=2.

Type III secretion, contact-dependent model for the intracellular development of chlamydia.

The medically significant genus Chlamydia is a class of obligate intracellular bacterial pathogens that replicate within vacuoles in host eukaryotic cells termed inclusions. Chlamydia's developmental cycle involves two forms; an infectious extracellular form, known as an elementary body (EB), and a non-infectious form, known as the reticulate body (RB), that replicates inside the vacuoles of the host cells. The RB surface is covered in projections that are in intimate contact with the inclusion membrane.

Protein expression profiles of Chlamydia pneumoniae in models of persistence versus those of heat shock stress response.

Chlamydia pneumoniae is an obligate intracellular pathogen that causes both acute and chronic human disease. Several in vitro models of chlamydial persistence have been established to mimic chlamydial persistence in vivo. We determined the expression patterns of 52 C.

Improved prediction of bacterial transcription start sites.

Motivation: Identifying bacterial promoters is an important step towards understanding gene regulation. In this paper, we address the problem of predicting the location of promoters and their transcription start sites (TSSs) in Escherichia coli. The accepted method for this problem is to use position weight matrices (PWMs), which define conserved motifs at the sigma-factor binding site.

Differential expression of chlamydial signal transduction genes in normal and interferon gamma-induced persistent Chlamydophila pneumoniae infections.

Characteristic features of the persistent chlamydial developmental cycle, associated with chronic infections in both humans and animals, include the generation of non-replicative, morphologically aberrant bodies which are distinct from normal propagating reticulate bodies. Previous studies have correlated these morphological and metabolic changes with differential expression of diverse functional subsets of chlamydial genes. To further investigate these correlations, we compared mRNA expression of predicted chlamydial signal transduction genes between normal Chlamydophila pneumoniae A-03 infections in HEp-2 cells and those treated with gamma interferon (IFN-gamma) by using real-time RT-PCR.

Multiple genotypes of Chlamydia pneumoniae identified in human carotid plaque.

Chlamydia pneumoniae is an obligate intracellular respiratory pathogen that causes 10 % of community-acquired pneumonia and has been associated with cardiovascular disease. Both whole-genome sequencing and specific gene typing suggest that there is relatively little genetic variation in human isolates of C. pneumoniae.

Discordant detection of Chlamydia pneumoniae in patients with carotid artery disease using polymerase chain reaction, immunofluorescence microscopy and serological methods.

Aim: To determine the presence of Chlamydia pneumoniae in carotid plaque and peripheral blood mononuclear cells (PBMCs) using a combination of serology, direct antigen detection by immunofluorescence (IF) microscopy and polymerase chain reaction (PCR), and to compare the results obtained from each assay.

Methods: A total of 54 atherosclerotic carotid plaques were tested for the presence of Chlamydia by PCR and IF methods. Of these 54 patients with carotid artery disease (CAD), 43 were also tested for the presence of C.

Interaction of microbiology and pathology in women undergoing investigations for infertility.

Background: Cases of endometriosis with no tubal damage are associated with infertility, suggesting an immunological rather than mechanical barrier to reproduction. Laparoscopy and falloposcopy results of clinically asymptomatic women undergoing investigation of infertility were correlated with the outcomes of microbiological screening for Chlamydia trachomatis, Mycoplasma pneumoniae, Mycoplasma hominis, ureaplasma species, Neisseria gonorrhoeae, Neisseria meningitidis and Chlamydia pneumoniae.

Methods: A total of 44 women presenting to a hospital IVF service for laparoscopic or laparoscopic/falloposcopic investigation of infertility provided endocervical swabs, fallopian tube washings, and peripheral whole blood for analysis.

The structures of higher boron halides B8X12(X = F, Cl, Br and I) by gas-phase electron diffraction and ab initio calculations.

The structure of B8F12 has been shown by gas electron diffraction and computational methods (up to MP2/6-31+G*) to have the same highly asymmetric form observed in crystalline phases. The structure can be regarded as derived from a central B2 group, bridged by two BF2 groups to give a central B4 core that is folded, not planar, and with a very short bond [164.3 pm calculated, 164.

Natriuretic peptides, respiratory disease, and the right heart.

It is well-recognized that atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are raised in conditions with ventricular volume and pressure overload. In addition to this established role in left ventricular congestive cardiac failure, there is good evidence that BNP has a diagnostic role in right ventricular (RV) dysfunction and pulmonary arterial hypertension (PAH). For example, BNP levels can be used to differentiate between dyspneic patients with pure respiratory defects and those with RV dysfunction.

The natriuretic peptides and their role in disorders of right heart dysfunction and pulmonary hypertension.

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are increased in conditions with cardiac ventricular volume and pressure overload. The general physiological and potential therapeutic roles of natriuretic peptides in respiratory disease, right ventricular (RV) dysfunction, and pulmonary arterial hypertension (PAH) are reviewed. BNP levels can be used to differentiate between dyspneic patients with a pure respiratory defect and those with RV dysfunction.

Evaluation of tetracycline, erythromycin, penicillin and streptomycin for decontaminating koala semen contaminated in vitro with chlamydiae.

Semen from seven koalas was extended in a tris-citrate glucose diluent containing one of four antibiotics at different concentrations and then contaminated with a standard concentration of chlamydiae. These semen preparations were then tested for residual chlamydial viability by an in vitro cell culture assay, and any detrimental effect of the antibiotics on the motility and viability of the sperm was assessed. Penicillin at 25 iu/ml or more, erythromycin at 1000 microg/ml or more and tetracycline at 200 microg/ml or more were highly effective at rendering the chlamydiae non-viable, but streptomycin showed no antichlamydial activity.

Wide range of Chlamydiales types detected in native Australian mammals.

The Chlamydiales are a unique order of intracellular bacterial pathogens that cause significant disease of birds and animals, including humans. The recent development of a Chlamydiales-specific 16S rDNA polymerase chain reaction (PCR) assay has enabled the identification of Chlamydiales DNA from an increasing range of hosts and environmental sources. Whereas the Australian marsupial, the koala, has previously been shown to harbour several Chlamydiales types, no other Australian marsupials have been analysed.

Molecular evidence for novel chlamydial infections in the koala (Phascolarctos cinereus).

Chlamydia-related disease has a detrimental effect on Australia's free-range koala (Phascolarctos cinereus) populations. The chlamydial species responsible for ocular, urogenital and respiratory disease in the koala have previously been identified as Chlamydophila pecorum and Chlamydophila pneumoniae. Epizootiology studies have therefore used species specific PCR assays to detect chlamydial infections.

Immunopathogenesis of chlamydia trachomatis infections in women.

Objective: To develop a model of pathogenesis by which Chlamydia trachomatis progresses from acute to chronic infection, and finally serious disease (salpingitis, tubal occlusion).

Design: Review of current literature located through web-based Medline searches using key words: Chlamydia trachomatis, immunology, cytokines, heat shock protein, infertility.

Result(s): Cell-mediated immune mechanisms appear to be critical in determining whether acute infection is resolved or progresses into chronicity with pathological outcome.

Distribution of Chlamydia pneumoniae DNA in atherosclerotic carotid arteries: significance for sampling procedures.

Despite extensive efforts to confirm a direct association between Chlamydia pneumoniae and atherosclerosis, different laboratories continue to report a large variability in detection rates. In this study, we analyzed multiple sections from atherosclerotic carotid arteries from 10 endartectomy patients to determine the location of C. pneumoniae DNA and the number of sections of the plaque required for analysis to obtain a 95% confidence of detecting the bacterium.

Differential expression of genes encoding membrane proteins between acute and continuous Chlamydia pneumoniae infections.

Chlamydia pneumoniae is associated with several chronic human diseases, including chronic obstructive pulmonary disease and atherosclerotic cardiovascular disease. During chronic disease, organisms are believed to exist in a persistent phase that is not well understood at the genetic level. Long-term in vitro continuous infections are spontaneously persistent and are less susceptible than in vitro acute infections to treatment with antibiotics, and are therefore particularly relevant as an in vitro model of in vivo chronic disease.

A mathematical model for the investigation of the Th1 immune response to Chlamydia trachomatis.

Chlamydia are bacterial pathogens of humans and animals causing the important human diseases trachoma, sexually transmitted chlamydial disease and pneumonia. Of the human chlamydial diseases, sexually transmitted disease caused by Chlamydia trachomatis is a major public health concern. Chlamydia trachomatis replicates intracellularly and is characterised by a complex developmental cycle.